TQ5M31 View Datasheet(PDF) - TriQuint Semiconductor
Part Name
Description
MFG CO.
'TQ5M31' PDF : 16 Pages View PDF
TQ5M31
Data Sheet
LO Power Level
The TQ5M31 performance is specified with an LO power of -4
dBm. However, satisfactory performance can be achieved
with LO drive levels in the range of -7 dBm to 0 dBm. Gain
and input IP3 can be traded off by varying the LO input power.
At lower LO drive levels, the gain increases and the input IP3
decreases or vise versa. DC current and output IP3 remain
approximately constant.
Mixer RF (Pin 4)
The Mixer RF port of the TQ-5M31 provides a good,
broadband match to 50 ohms over the entire RF frequency
range. This minimizes IF leakage, and more importantly,
prevents noise and unwanted signals at or near the IF
frequency from being injected and degrading noise
performance.
Ground (Pin 5)
Connect to an adequate RF and DC ground.
Mixer IF Port (Pin 6)
The Mixer IF output is an "open-drain" configuration, allowing
efficient matching to various filter types at various IF
frequencies. An optimum lumped-element matching network
must be designed for maximum power gain and output third
order intercept.
While tuning for the IF frequency, one has to consider the
source impedance of the IF Amplifier. The IF frequency can
be tuned from 45 to 500 MHz by varying component values of
the IF output circuit. Pin 6 also provides bias injection.
It is recommended that the value of C3 be kept between 12
and 20 pF to optimize the IF match. For good isolation, the
value of C4 should be no less than 22 pF. Decoupling
components for the power supply are included on the
evaluation board.
The decoupling components consist of a 10Ω resistor, and
0.01µF shunt capacitors. These components prevent reflected
noise or other spurious signals from leaking through the Vdd
line onto other ports.
In the user's application, the IF output is most commonly
connected to a narrow band SAW or crystal filter with
impedances from 300 -1000Ω with 1 - 2 pF of capacitance. A
conjugate match to the higher filter impedances is generally
less sensitive than matching to 50Ω . When verifying or
adjusting the matching circuit on the prototype circuit board,
the LO drive should be injected at Pin 3 at the nominal power
level (-4 dBm), since the LO level affects the IF port
impedance.
Suggested IF Matching Network
There are several networks that can be used to properly
match the IF port to the SAW or crystal IF filter. The mixer
supply voltage is applied through the IF port, so the matching
circuit topology must contain either an RF choke or shunt
inductor.
The shunt L, series C, shunt C configuration is the simplest
and requires the fewest components. DC current can be
easily injected through the shunt inductor and the series C
provides a DC block, if needed. The shunt C, in particular can
be used to improve the return loss and to reduce the LO
leakage.
14
For additional information and latest specifications, see our website: www.triquint.com
Share Link: 
